Regular readers of this blog might remember that I learned of the term "energetic felling" when they did a controlled demolition of the Kosciusko Bridges in New York City. I was going to add these videos as an update to the post about the Hard Rock Hotel construction tragedy in New Orleans. (The final death count is three workers.) But I came across enough material that it is worthy of its own post. I read a lot of Facebook comments in crane groups that were very critical of this procedure.
"Sticking the landing" is good in gymnastics. It is not good in demolition.
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| Screenshot (source) Albert Bailer While waiting , I told the wife how good the explosive experts were , that they could figure out where to place the charges so the crane would be on the ground or at least safe enough to take it apart . After the detonation I looked at her and said , then sometime something goes wrong , like this . Eugene Hassett nailed the landing. 5.7, 5.5, 5.6, 5.6 [I thought of the "sticking the landing" commentary before I read these comments.] |
Some quotes from NBCchicago:
Thundering explosions toppled two cranes Sunday that had loomed precariously for days over a partially collapsed hotel in New Orleans, in what city officials hailed as a success and said efforts now would focus on retrieving two bodies still inside the ruined building.
A sewer line was damaged as well, but the mayor said padding that was designed to protect the gas and electric lines — a major concern — worked as expected.
"I do not think it could have gone much better," said Fire Chief Tim McConnell, flanking the mayor.I'll bet it was luck, not padding, that caused a sewer line to be stabbed instead of a gas line.
The city officials did not fool the editor because the headline was:
Hotel Collapse: 2 Leaning Cranes Felled 'Exactly' as Planned
Note the quotes around "exactly."
One worker has already been recovered. After they recover the remaining two, the Mayor announced the entire building will be torn down.
One worker has already been recovered. After they recover the remaining two, the Mayor announced the entire building will be torn down.
(new window) (source)
One of the reasons the demolition was delayed from Friday to Saturday to Sunday was because the demolition company would not do the job until someone had paid them the $5m fee. (I've seen conflicting reports that the fee was paid by the construction company or by Hard Rock.) And the authorities kept expanding the exclusion zones as they had more time to think about it. Nobody was supposed to be in the red zone. People in the orange zone were to be indoors with windows closed. No traffic was allowed to enter the yellow zone.
WGNO video appears to be the source of the above broadcast.
(new window) This video has two views
The more I look at this video, the more I realize how lucky they were. Notice in the lower-left corner that a flying member almost knocked the stuck tower over into a building.
At work we would talk about the "laugh test." In this case, can you hear "as planned" without laughing. If they planned that the tower would stab a sewer instead of a gas pipe, that the jib would cartwheel down the street instead of into a building, and that the flying member wasn't over far enough to significantly move the tower, I'd like to read that plan.
It is interesting that the Chicago Tribune also put "exactly" in quotes.
(new window) A 4WWL report includes a slow motion version of "the video."
In this video, "engineers" claim that even the stable looking crane is unstable. But after you read and see so many questionable claims, you don't know what to believe anymore. The lower floors where built for commercial space and a garage. I think, freely translated, that means that it was the floors that people would live in that pancaked. When they determine the root cause, then we have to ask how many other buildings in New Orleans were built with the same flaw. If it was corruption, that could be a lot of buildings with a lot of different issues. I know when they built a building in Downers Grove, IL, they would sometimes pour the first concrete from a truck into some little cylinders. I confirmed that they would be saved for quality control reasons. The title of the video, "Why did the Hard Rock Hotel collapse? Engineers investigate," is click bait. Instead, they found a professor who was willing to speculate how much of the building would have to be torn down. At first she thought they could save the core. Later she hedged her bets and said they may have to tear down the whole thing. As I have said, I saw a video clip of the Mayor announcing the whole thing is going to be torn down, including the foundations.
This video is clips of raw footage. It was the second clip that let me see that it was the counterweights of the crane that almost knocked over the tower that was struck in the street. It did hit the tower and make it sway. But fortunately, the tower was poked deep enough into the ground that it swayed back to a vertical position.
Adam Ryan posted four photos from which I cropped the black margins.
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| 4WWL Screenshot |
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| Screenshot from first video posted by Slim Cooper Not a good day at the hard rock hotel collapse. Tower crane demo did not go as planned. One crane is hanging on the building and not on the tower anymore, the other is upside down with most of its tower sticking straight up. Sorry about the quality of videos, these were live as it happened off a news broadcast. Richard Ferrero The part sticking straight actually pierced the street and a few sewer lines! Kind of like a really big lawn dart. Slim Cooper I'm not trying to second guess the demo company but from what I've seen of the plan on how it was intended to go, I just don't see how it could have worked. They said they wanted to fold the booms so they fell against the towers, then bring it all down together. Weren't both booms swung out over the existing building? So what did they think was going to happen when they blew the pennant wires? I would have thought if that was the plan then leave the pennants and blow the boom about halfway so it folds in half, the pennants and the heel pins would keep everything tight to the tower. The other thing is even if that did work, delay blowing the tower and give the booms enough time to get to the tower. Ok, that's all my armchair opinion, lol. Just hope nobody else gets hurt finishing the job. Also, I'm sorry if my terminology is off, never worked around tower cranes, just crawlers and derricks. Work safe everyone. [We can see the top of the tower part that got stuck in the street standing vertically. But the brown diagonal boom in this screen shot is flying to the left. If it fell at a slightly different angle, how much of an adjacent building would it have taken out? Do any city officials understand this was not a success, this was luck?] |
WGNO video appears to be the source of the above broadcast.
(new window) This video has two views
The more I look at this video, the more I realize how lucky they were. Notice in the lower-left corner that a flying member almost knocked the stuck tower over into a building.
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| 19WLTX Screenshot excerpt (source) |
It is interesting that the Chicago Tribune also put "exactly" in quotes.
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| Chicago Tribune, Oct 21, 2019 |
(new window) A 4WWL report includes a slow motion version of "the video."
In this video, "engineers" claim that even the stable looking crane is unstable. But after you read and see so many questionable claims, you don't know what to believe anymore. The lower floors where built for commercial space and a garage. I think, freely translated, that means that it was the floors that people would live in that pancaked. When they determine the root cause, then we have to ask how many other buildings in New Orleans were built with the same flaw. If it was corruption, that could be a lot of buildings with a lot of different issues. I know when they built a building in Downers Grove, IL, they would sometimes pour the first concrete from a truck into some little cylinders. I confirmed that they would be saved for quality control reasons. The title of the video, "Why did the Hard Rock Hotel collapse? Engineers investigate," is click bait. Instead, they found a professor who was willing to speculate how much of the building would have to be torn down. At first she thought they could save the core. Later she hedged her bets and said they may have to tear down the whole thing. As I have said, I saw a video clip of the Mayor announcing the whole thing is going to be torn down, including the foundations.
This video is clips of raw footage. It was the second clip that let me see that it was the counterweights of the crane that almost knocked over the tower that was struck in the street. It did hit the tower and make it sway. But fortunately, the tower was poked deep enough into the ground that it swayed back to a vertical position.
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| Screenshot |
Adam Ryan posted four photos from which I cropped the black margins.
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| 1 Adam Ryan It busted a 24” sewer line. |
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| 3 [If the angle was a little different, the jib would have left a "mark" on the building to the right. Given the way the metal is twisted where the jib attaches to the tower, this angle that put it into the street was just luck. To claim that the demolition went "exactly as planned" and that it was a "success" means the plan must have included pixie dust or other magic technology that I don't know about. Or if the plan was simply to use explosions to remove some evidence as I have seen speculated by some Facebook comments, then the energetic felling did go exactly as planned. (I don't buy the speculation that the tower cranes were a cause of the collapse. And at least one of them was unstable and increased the risk of the rescue and investigation activities.)] |
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| Chuck Ellis posted NOLA [The "stuck landing"] Ryan Abbott That A Frame must be 20’ into the street. I wonder how many sewer and other services it killed. [A 24" sewer line]Will T Henson One tough cab, heavy, wondering why the jacking frame was at the top.Jesse Sommers Me and a couple other guys were wonderin the same thing.....it shouldnt have been left up as high as it was.... |
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